This invention relates to a new and improved cutting insert, used in deep grooving operations, having a unique chip controlling configuration. The leading surface of the insert includes a V-shaped ridge spaced from the cutting edge thereof. The V-shaped ridge is oriented such that the apex portion thereof is disposed closest to the cutting edge. A groove is also provided on the leading surface of the insert which is contiguous with the V-shaped ridge and extends towards the cutting edge. In one embodiment of the subject invention, the groove is also contiguous with the cutting edge and defines a flattened chip breaking area. In another embodiment of the subject invention, a planar land area is provided which is disposed between the cutting edge and the groove and is contiguous with both. The chip breaking configuration functions to reduce chip width and lengths.
In the prior art, replaceable cutting inserts have been developed for use with varying types of cutting tools such as milling, boring or grooving devices. The cutting insert, which is usually formed from a block of cemented carbide material, includes at least one sharpened cutting edge. The main advantage in using replaceable inserts is that when the cutting edge becomes worn, a fresh insert may be rapidly exchanged with the worn inset, thereby avoiding the down time associated with resharpening a tool having a fixed blade.
With the development of the cemented carbide materials, cutting speeds have increased dramatically. While the increased feed rates and cutting depths are effective in reducing manufacturing costs, certain problems associated with higher cutting speeds have occurred. More specifically, at low speed, the metal which was shaved away during a cutting operation would slowly fall away from the workpiece and present no difficulties. However, with increased feed rates and cutting depths, metal, removed from the workpiece, is in the form of a thin strip of material. This thin shaving of metal is rapidly produced and if not properly controlled, will damage the workpiece and poses a safety hazard to the operator. For example, in a grooving operation, a coil of metal is produced which often runs out of the groove and along the outer diameter of the workpiece, abrading its finish. Frequently, the snaking coil of metal breaks off in a large chip, flying away at a fast speed, posing serious safety problems for the operator of the machine. Another shortcoming associated with the prior art inserts in grooving operations is that metal chips, which had a width equal to the width of the groove, are caught or become bound in the machined grooves, thereby causing an increase in vibrations and cutting edge breakage. In response to these shortcomings, a number of inserts have been developed which include a chip breaking groove, formed on the leading surface of the insert, which function to break the coils into smaller, manageable chips. Examples of inserts having a chip controlling groove can be found in U.S. Pat. No. 3,395,434 issued Aug. 6, 1968, to Wirfelt, and U.S. Pat. No. 3,407,467 issued Oct. 29, 1968 also to Wirfelt. In these patents, cutting inserts are disclosed having chip breaking grooves disposed around the periphery of the insert, on the leading surface thereof, for breaking a snaking coil of metal into small chips. Other examples of cutting tools having chip breaking configurations can be found in U.S. Pat. No. 2,779,992, issued Feb. 5, 1957 to Hayes; U.S. Pat. No. 2,831,240, issued Apr. 22, 1958 to Maurer; U.S. Pat. No. 2,855,657 issued Oct. 14, 1958 to Erhardt; U.S. Pat. No. 3,487,515, issued Jan. 6, 1970 to Contrucci; U.S. Pat. No. 3,707,747, issued Jan. 2, 1973 to Falk; U.S. Pat. No. 3,815,191, issued Jan. 11, 1974 to Holma; U.S. Pat. No. 3,947,937, issued Apr. 6, 1976 to Hertel; and U.S. Design Pat. No. 28,425, issued Mar. 29, 1898 to Moon.
As noted above, one of the shortcomings associated with a deep grooving operation in particular, was that the removed metal coil tended to get caught and bound in the groove. The above cited patents, which contain chip controlling grooves for breaking a snaking coil into small pieces, failed to prevent the binding of the coil with a machined groove.
Accordingly, it is an object of the subject invention to provide a new and improved insert for use in conjunction with a deep grooving tool which functions to break metal coils removed during the grooving operation into small chips.
It is another object of the subject invention to provide a new and improved cutting insert for use with a deep grooving tool which simultaneously functions to reduce the width of chips to prevent their binding in the groove, thereby eliminating chip crowding and reducing vibrations and cutting edge breakage.
It is a further object of the subject invention to provide a new and improved cutting insert having a chip controlling configuration which functions to break removed metal into small chips, thereby preventing damage to the workpiece and facilitating easy disposal thereof.
It is still another object of the subject invention to provide a new and improved cutting insert for use with a deep grooving tool having a chip controlling configuration formed on the leading surface thereof, which includes a V-shaped ridge spaced from the cutting edge, and a groove contiguous with said ridge and extending towards said cutting edge for breaking the chips into small pieces and producing chips having reduced widths.